And are charter schools about reading and math? Cherry picking results is easy to show whatever you like.
Charter schools are about - whatever each is constituted to be about. Like you can't go to a hardware store and grab a random tool and rate it on how well it drills holes. You shouldn't rate charter schools on your favorite metric. Some are about upper-class folk raising their kids with better music and art appreciation. Others are about escaping backward school boards. Sometimes they are in areas so backward, that the charter school still underperforms the national average. But if its an improvement for that area, its an improvement.
The "sacrifices" involved in any decision here are actual children too.
For example for me specialization couldn't come too early. Specializing even at age 12 would have been fine. Everything else could have fallen by the wayside, I only was interested in and good at exactly one thing and only at University did I finally meet anybody who actually challenged me, only there did I find specialisations within the specialisation that were all attractive. In some ways the last 3-4 years of school were just waiting.
For plenty of other kids they got all the way to an undergraduate degree in some general subject area they didn't care about, still with no clear idea what they were about, no real direction, forcing them to specialize earlier would have hurt them severely by cutting off options.
Without fairly intensive Chemistry (and preferably some Biology) by age sixteen, you are not going to become a good medical doctor. Without putting many hours a week into mathematics (not just enough to grasp a vaguely analytical subject like engineering, serious fundamental mathematics) by age eighteen you are never going to become a serious mathematician. And sucks to be you if, aged twenty-five, you at last find out you are a natural with a basketball, or at soccer, or dozens of other sports which require peak physical performance that's unattainable in middle age.
All our options here suck, somewhere a kid will be betrayed by whatever happens, if they're able to specialise, some of them will pick wrong and regret it. No fault to them, just bad luck. If they can't specialise the mandatory general achievement will prevent some of the most talented in specific fields from ever achieving what was possible.
I have no recommendation here, just commiserations.
There are plenty of short term advantages to specialization. But, diminishing returns generally apply and the standard public school curriculum is a relatively low bar. So, IMO we should generally stick with them, but after that the sky's the limit.
That said, you have a good point that some fields really do require a lot of early work. I just think they should be added as supplement not simply replacing the foundations of a good education.
Charter schools are about - whatever each is constituted to be about. Like you can't go to a hardware store and grab a random tool and rate it on how well it drills holes. You shouldn't rate charter schools on your favorite metric. Some are about upper-class folk raising their kids with better music and art appreciation. Others are about escaping backward school boards. Sometimes they are in areas so backward, that the charter school still underperforms the national average. But if its an improvement for that area, its an improvement.